Method and apparatus for controlling moving vehicles



April 2, 1946.

"w. L MAXSON ETAL METHOD AND APPARATUS FOR CONTROLLING MOVING VEHICLES Filed Dec. 1, 1959 15 Sheets-Sheet 1 IN VENTORS WILLIAM L. 1M4 xso/v FREDERICK m LUTZ PETER J. mums/v METH AND APPARATUS FOR CONTROLLING MOVING VEHICLES Filed Dec. 1, 1959 l3 Sheets-Sheet 2 INVENTORS WILLIAM L. MAXSON FREDERICK W. LUTZ PETER J. M LAREN N/CHO A8, IIFEDOTOFF 7 -164,," 7 I ATTQRNEYJ Apnl 2, 1946. w. L MAXSON- ETAL 2,397,476

METHOD AND APPARATUS FOR CONTROLLING MOVING VEHICLES FiledDec. 1, 1939, 1:5 Sheets-$heet s INVENTORS WILL 1AM L. MA XSON BY FREDERICK m LUl'Z PETER J. m LAREN Z N/CfO S DOTOFF ATTORNEY I April 2, 1946.

METHOD AND APPARATUS FOR CONTROLLIIG MOVING VEHICLES W. L. MAXSON ET AL Filed Dec. 1, 1939 15 SheetS -Sheet 5 PETER J. MLAREN My s oororr 1; ATTORNEYJ' i Q. \g I I q m M 1 1 I T I T INVENTORS WILL/AM 1.. wxsou BY FREDER/Ck n. LUTZ p 1946- -w. L. MAXSON EI'AL 2,397,476

METHOD AND APPARATUS FOR CONTROLLING MOVING VEHICLES Filed Dec. 1, 1959 13 Sheets-Sheet 6 BY FREDERICK m LUTZ PETER J. mums/v N/ MFEDOTOFF MA TORN Y;

April 2, 194.6; w MAXSQNI ET AL METHOD AND APPARATUS FOR CONTROLLING MOVING, VEHZITCIIJESIY'Q I Filed Dec. 1, 1939 13 shetgsli eii I A il 1' A N 7 Q5 l" g5 'lb "H Aim I m mil N N a 2' INVENTORS AL/AM L". MA xso/v FREDERICK m LUTZ BY ATTORNEYS PETER "cu/PEN r H LAs. ursoororr April 2, 1946. w. 1. MAXSQN ml 2,397,476 METHOD AND APPARATUS FOR CONTROLLING MOVING VEHICLES Filed Dec. 1, 1939 1s sheets-sheet a 4 INVENTORS WILLIAM L. MAXSON .r F. Hum .050 LRD .4: WLF 6. K c mJ ska wmw R Fmm BY ATWYS Apiil 2, 1946. w, L xs N E 2,397,476

METHOD AND APPARATUS FOR CONTROLLING MOVING VEHICLES Filed Dec. 1, 1939 13 Sheets-Sheet 9 INVENTORS 7 WILLIAM L. MAXSON FREDERICK I LUTZ PETER J. MLAREN April 2, 1946 v w. I... MAXSON ETAL 9 METHOD AND APPARATUS FOR CONTROLLING MOVING VEHICLES Filed Dec. 1, 1959 13 Sheets-Sheet 10 I INVENTORS WILLIAM-L. MAXSON BY FREDERICK m LUTZ ATTORNEYS PETER J. MLAREN April 2, 1946. w. L. MAxsoN ET AL 3 5 METHOD AND APPARATUS FOR CONTROLLING MOVING VEHICLES Filgd Dec. 1, 1959 13 Sheets-Sheet 11 INVENTORS W/L LIAM L. MA XSON FREDERICK n. LUTZ PETER J. MLARN NICHOLAS MFEDOTGfF BY EArrOR/s/EYS 'AIlA-a 7 A ril 2,1946; w. L. MAXSON ETAL 2,397;476' METHOD AND APPARATUS FOR CONTROLLING MOVING VEHICLES Filed Dec. 1, 1939 13 SheetSeSheet' 12 INVENTORS 5 AM L. MAXSON BY mum/cw n: LUTZ PETER J. MCLAREN I w ura'oororr ATTORNEY;

April 2, 1946. w, L. MAXSON EI'AL 2,397,476v

METHOD AND' APPARATUS FOR CONTROLLING MOVING VEHICLES I I Filed Dec. 1:5 She'ts -Sheet 15 lhllllIIIlllll]IHHIIIIIHIIHIIIII -INVENTORS WILLIAM L. MA XSON FREDERVG'K m LUTZ Patented Apr. .2, 1946 METHOD AND APPARATUS FOR con- TROLLINGIMOVING VEHICLES William L. Maxson, South Orange, N. J., and

Frederick W. Lutz, Garden City, Peter J. McLaren, New York, and Nicholas V. Fedotofl', L'ynbrook, N. Y., assignors, by mesne assignments, to The W. L. Maxson Corporation, New York, N. Y., a corporation of New York Application December 1,1939, Serial No. 307,074

2 Claims. (01. 244-11) This invention relates to the control of one or more parts of a device from a remote point by means of electrical impulses and more espe- -cially to the control of certain parts of an air-'- plane, ship or other movable vehicle or to a part or parts of an object or objects carried by such vehicle. As illustrations of the use to which the invention is adapted, it' may be employed to control the elevators, ailerons and rudder of anairplane, the engine throttle for control of the speed of the plane, flaps of the plane for landing purposes, instruments carried by the plane such as radio receivers or transmitters, cameras,

or to control devices adapted to release objects such as bombs, etc., from airplanes.

A still further object is to provideforthe. eontrol of two different control devices or members on an airplane or other vehicle by means of a single control handle located at a ground station or in another airplane orvehicle. The control handle is preferably mounted for universal movement similar to the control stick of an airplane,

. so that it may be rotated about ,eithera lateral In pursuance of the invention, the controlof parts of or objects carried by a moving vehicle is effected by, radio signals and preferably by the transmission to the vehicle of a modulated carrier wave of radio frequency, a suitable radio receiver being provided on the vehicle to receive the control signals and transmit them to suitableapparatus which accomplishes thedesired control of the intended part or parts.

It is an object of the invention to effect the control of the desired part or parts through any desired extent or angle of adjustment by the transmission of pulses of energy of controlled duration and to provide at the controlled device, T

suitable mechanism which effects the control in accordance with the duration of thepulses.

To provide energycpnlses of any desired durationfit is'a-Iurther object of the inventionto provide at the transmitting station a novel means and' method for controlling the action of one or more control channels which effect the modula-' vtion of the transmitted carrier wave.

ance of this object, the controlof the modulator is preferably effected by a novel circuit arrangement which includes a relay and a relay control device;

Another object is to provide suitable mechanism for the control'of a movable controlled part on the airplane or other vehicle by a control handle located at a ground station or'in another vehicle, the controlled member moving in one In pursu- V which: I 1

Fig. 1 is a schematic circuit diagram of a radio axis or a longitudinal axis or about both axes simultaneously. v V I A further object isto provide at the ground control station a rotatable platform on which the operator may be seated and on which is disposed within his easy reach the several control memberswhich control the parts of the airplane which determine its flight. Suitable means for rotating the platform, either by the operator seated thereon or by an assistant standing 'on the platform, are provided so that the operator may keep the controlled airplane constantly in view as it moves in accordance with his manipulation of the control members.

Other and further objects of the invention will become apparent to those skilled in the art as the description thereof proceeds. For a 'better understanding of the invention, however, referenceis made to the accompanying drawings, in

transmission system embodying the invention and also showing certain mechanical control features schematically; i V

Fig. 2 is "a schematic diagram showing an extension of the transmitting system of Fig. 1 to provide-roithe remote control of,the rudder and throttle offthe airplane; g

Fig. 3 is a schematicpircuit diagram showing a further extensionof the-transmitting system of Fig. l to provide for emergen'cyor spare apparatusadapted to be connected in the transmission systeminstead of certain apparatus shown-schedirection or in an opposite direction in accordance with the movement of the control handle in one direction or in an opposite direction from a neutral position thereof. The mechanism also provides for the movement of the controlled memher or part in accordance with the. extent of adjustment or angle of rotation'of the controlhandle.

matically in Figs. 1 and 2 and for supplementary miniature controls; 7 v

Fig. 4 is a schematic circuitdiagram of a-radio receivingsystem embodying the invention-alsoshowing certain features of the controlled apparatus schematically; a v Fig. 5 isa schematic diagram showing an extension of the receiving system of Fig. 4;

Fig. 6 is a schematic diagram showing a further extension of the receiving system of Fig. 4 and showing schematically an embodiment of the invention for controlling the rudder andthrottle of'an airplane;

Figs. 11 and 12 are sectional views of the throt-f tie-control lever and associated ratus;

Fig. 13 is a fragmentary front elevation of an airplane showing diagrammatically certain concontrol appatrol apparatus embodying the invention mounted thereon;

Fig. 14 is a fragmentary plan view of an airplane showing control apparatus embodying the invention mounted thereon;

Fig. '15 is a fragmentary view showing the clutching and declutching arrangement for the control apparatus embodying the invention;

Fig. 16 is a front view of the remote control throttle operating device with its mounting and supporting housing shown in section;

Fig. 17 is a sectional view of the throttle operating device taken on the line I'I-II of Fig. 16; i

Fig. 18 is a view showing the impulse motors and their associated driving gearing of the throttle operating device and; v

Fig. 19 is a sectional view of the gearing and its supporting housing taken on the line I 9-49 of Fig. '18.

Referring to Fig. 1,'a rotatable control shaft I is shown as provided with a control lever or stick primed, double primed, etc. Differentiator D' and its connected relay I8 are connected to resistor over which the contact arm 4' carried by shaft I operates, the resistor 5 being connected to the primarywinding 6' of the input transformer X through the circuit shown including the switch 9.

Movement of the handle 2 to rotate the shaft 3 in one direction may tilt the elevators upward from their mid-position and its movement in the opposite direction causes them to tilt downwards.

Movement of handle 2 to rotate shaft 3 in one direction will then serve to control the elevators to elevate the airplane whereas its movement in the opposite direction controls them in a direction to depress the airplane.

Movement of the handle 2 to rotate shaft I in one direction may lower the right aileron from its normal wing position and raise the left aileron whereas its movement in the opposite direction causes the left aileron to be lowered from its normal wing position and the right aileron to be raised. Thus a movement, of the handle 2 inone direction to rotate shaft I will serve to bank the airplane on its left side and movementof handle 2 in the opposite direction will serve to bank it on its right side. I 1

For each of the relays of the'system, a pairof sources of signalling tone are provided such as 22 -23, l22-23', etc., eachsource comprising'an audio frequency oscillator, such as 24, whose output terminals are connected through the resist- 2 mounted for universal movement, in the man- 7 her of the usual control stick of an airplane, so that its rotation in a plane normal to the longitudinal axis of shaft I causes rotation of this shaft, while its rotation in a plane passing through 3 the axis of shaft I causes rotation of a shaft 3 mounted to rotate about-a lateral axis at right angles to shaft I. Rotation of lever 2 in intermediate planesobviously causes rotation of both the shafts'l and 3 simultaneously, A rheostat arm 4 mounted on shaft 3 serves to control a variable resistor 5' adapted to be connected in series with the primary winding 6 of an iron'core transformer X and-a battery I (Fig. 3) through the leads shown and switches 8 (Fig. 3) ,"and I0 (Fig. 1).; Transformer X comprises one of the comtype of transmitting antenna may be provided.

ponents of a diflerentiator designated generally j by the reference letter D and which comprises the secondary winding II having its opposite ends connected to the control grids I2, I2 of the vacuumtubes I3, I35. The plates I4, I4 of these tubes are connected to the ends of a circuit in- 1 cluding the series connected resistors I5, I5, I5",

an intermediate point of resistor I5" being connected through adjustable contactIG and the lead shown-to the positive terminal of a battery ll (Fig. 3) whose negative terminal is grounded tact I6 is adjusted so "that normally no current passes through the winding of relay I8 and-its armature I9 remains in the mid-position shown.

It will be understood that a diiferentiator similar to D operating a'polarized relay similar to I8 parts being designated by similar numerals l as shown. The plates I4, M are also connected g to the} terminals of a polarized relay I8 provided with an armature I9 which cooperates with the 1 upper and lower contacts20 and 2|. Sliding conan antenna 36.

ance network 25, 26, 21 and transformer 28 to the tone bus" bars 28. The output terminals of tone generator 23 are shown connectedto the primary of a transformer 28 through the resist ance network 30, 3|, and 32, the several resistors of the networks being adjustable, as indicated, in the, preferred construction. The tone bus bars 29 are connected by any suitable means, such as the transformer 33 and variable resistor 34 to the modulator input terminals of a radio frequency transmitter 35 arranged to generate a carrier current of constant frequency. The output terminals of transmitter 35 are connected to When the transmitting equipment is located at a ground station, one of the transmitter terminals may be connected to ground, as shown, and when the transmitting equipment is located on a movable vehicle, as, for example, in another airplane, any suitable known The tone frequency generators 22 23; I2-23f,

22"23", etc., are preferably designed to gen-' erate currents of 1020, 1380, 1860, 2460, 3180,

4020, 4740 and 5340 cycles per second, respective-, 1y although it will be understood that other suit-1 able frequencies may be used. This particular series of frequencies has been selected toprovide for adequate selection and segregation, of the tone frequencies at the receiver. It also serves to prevent interference between harmonic frequencies and also that due to the sum and difference frequencies at the receiver. I i

In the operation of the transmitter, rotation of shaft 3 by the lever 2 changes the value of resistance 5 by an amount proportional to the throw of the lever,'thereby changing the value of the direct current passing through primary winding 6 of transformer X. If lever 2 is rotated clockwise about shaft 3 from the neutral or midposition shown, resistance '5 is increased, causing a pulse of current in secondarywinding II in one direction whereas if the lever is rotated counterclockwise about shaft 3 from the neutral position, the-pulse of current generated in secondary II will be in the opposite direction. A voltage is thus produced across secondary II, the direction of which depends on the direction of movement of lever 2 and the duration of which depends on the extent of its movement. This voltage is caused, through the amplifier tubes |3.|3', to operatepolarized relay l8 sothat its upper contact 20 is closed in response to a voltage in secondary II in one direction and its lower contact 2| closed response to a voltage pulse in the opposite direction. The relay contacts are selectively maintained closed.until lever 2 is brought to a position of rest, or during a desired time interval. Motion of lever 2 in a direction to cause armature l9 to close the lower contact 2| causes a short circuit of resistor 26, the switch 31 being closed in its position to the left. This prevents the tone frequency of 1020 cycles generated by oscillator 22 from being impressedon the bus bars 29 and transmitter 35 while lever 2 is in motion, the tone frequency of 1380 cycles being transmitted during the motion of the lever. Upon lever 2 becoming stationary, the grids l2 and .|2' are at the same potential and the plate circuits of tubes |3|3 are again balanced so that no current flows through the-windings of relay l8 and armature l9 returns to its open position. Thereupon both the tone frequencies of 1020 and 1380 cycles are transmitted.

Similarly,'motion of lever 2 in an opposite direction causes the plate circuits of tubes I3-I3 to become unbalanced so as to cause current to flow through the winding of relay |8 in such direction as to close the upper relay contact 20, thereby short circuiting resistor 30. This prevents the tone frequency of 1380 cycles by oscillator 23 from being impressed on bus bars 29 and transmitter 35. It thus follows that the rotation of control lever 2 in one direction causes one of the oscillator tone frequencies to be omitted from the transmission by. the carrier, wave, the durationof this omission being proportional to the extent of throw of lever 2. Similarly, rotation of the lever in';.the opposite direction causes the other oscillator tone frequencyrto be omitted from the transmission. Since, as will be explained later, the response of the controlled.

generated function of the, airplane depends onthe length of time that a tone is eliminated, it follows that for optimum results, the operator should move lever 2 at equal velocitiesat all times so as to secure the closest possible agreement in phase relationship between the control lever at the ground station and that on the aircraft. However, during the normal running of an airplane, the control lever is continuously passed through its neutral or mid-position, at which point synchronization of the control lever on the airplane and that at the ground station is reestablished in the event that thereis not a lationship. l

For the purpose of establishing this synchronization, shaft 3 is provided with the cams 38, 39 and 40, cam38 serving to open and close a switch 4|, cam 40 to open and close a switch 42 and cam 39 to open and closeboth of the switches 43 and 44. When lever2 is brought to the neutral position shown in Fig. 1, switches 43and 44 are both closed. Since the upper switch 43 is connected in parallel with upper relay contact 20 and armature i9 and the lower'switch 44 is connected in parallel with lower relay contact2| and armature i9, boththe tone frequenciesgenerated by the generators 22 and 23 'will be omitted from the transmission, which causes the controlled shaft close agreement in phase reon the airplane to be moved into its neutral position, by means to bedescribed later.

While lever 2 is being moved forward in the direction F the upper relay contact 20 closes, eliminating the tone frequencyof generator 23 from the transmission and causing the controlled member on the airplane toimove in the same direction. When lever 2 is stopped at its extreme forward position the armature I9 is returned to its neutral pos'itionbut cam 38 has closed the switch 4| which provides a short circuitacross upper contact 20 and armature 19, thereby continuing the omission of therto ne frequency of generator 23 from the transmissiom This omission causes the controlled member to continue its motion in the same direction until it reaches its extreme forward position when it is again in phase with control lever 2.; In a similar manner, movement of lever 2 rearwardly from its neutral po sition, as indicated by R, causes the'closure of lower relay contact 2| andthe omission of the tone frequency of'generator 22 from the transmission. When lever 2- is stopped at its extreme rearward position, the lower relay contact 2| is opened but cam 40 has closed the switch 42 which provides a short circuit across lower contact 2| and armature l9, thus continuing the omission of the tone frequency of generator '22 which causes the controlled member on the airplane to move rearwardly until it reaches its extreme rearward position, when it is again in phase with control lever 2. Means is thus provided for causing the tone frequencies of both generators 22 and 23 to be suppressed when lever 2 is in its neutral position; when it is moved forward, the frequency of generator 23 is omitted. This frequency continues to be omitted when the lever reaches its extreme forward position as long as it: remains in that position. When the lever is moved rearward from its neutral position the frequency of generator 22 is omitted and continues to-be omitted after the lever has reached its extreme-rearward position and as long as it remains there.

Movement of lever 2 about the longitudinal axis causes shaft to rotate and contact arm 4' to operate the diiferentiator D by changing the current through resistor 5. Movement of lever 2 to the left, as indicated byL. causes the closing of relay l8 thereby transmission and causing the controlled member I to move to the left. When lever 2 reaches its extreme leftward position, cam 45 causes theclo'suref of switch 46 which short circuits the resistor 26 and thus continues the suppression of the tone of generator 22' and movement of the controlled member into its extreme leftward position in phase with lever 2. Similarly, movement of lever 2 to the right as indicated by r, causes the closing of upper contact 20' of relay l8 and the consequent elimination of-the tone frequency of generator 23' from the transmission and the move-, ment of the controlled member to the right. When lever 2 is moved into its extreme position to the right, cam '4'| causes the closure of switch 48 which short circuits the resistor 30 and thus continues the elimination of the tone frequency of generator 23' and causes the movement of the controlled member into its extreme rightward position when it is again in the purpose of eliminating the tone frequencies of both generators 22' its neutral position, and thus bringing the controlled'member into its neutral or mid-position,

shaft is provided with a cam 49 which causes the phase with lever 2. For

'and23' when lever 2 is in .fler motors 29, as shown in Fig. 1.

closurev of the upper and lower switches ill-| which are connected with the lower and upper contacts 2| and respectively.

For the purpose ofreadily eliminating all the tones from the transmission, a bus bar switch Sl is provided, the closure of which serves to short circuit the bus bars 29. The closure of this switch,

. by the elimination of all the tone frequencies,

serves'to cause all the controlled members on the airplane to be automaticallyreturned to their mid Fig. 2, is a continuation of Fig. 1 and shows diagrammatically a portion ofthe means for con;

trolling the rudderand throttle of the controlled airplane. The control shaft 52 is providedwith a differential 53 to which the left and right rudder control pedals 54 55 are connected, suitable springs 51 connected to pedals 54, 55 urging the pedals to a neutral position. As in the case of the shaft 1 of Fig. 1, depression of pedal to rotate shaft. 52 counterclockwise causes differentiator D" and relay l8" to close the lower contact 2|" of the relay and eliminate the tone of generator 22". from the transmission. To continue the elimination, of this tone when shaft 52 has reached its extreme counterclockwise position,:the cam 58 and switch 58 are provided, the closure of switch 59 shortcircuitingarmature l9" and lower relay contact 2l".' Depression of the right pedal to rotate shaft 52 clockwise, causes difi'erentiator D" and relay l8' "to close the upper relay contact 20 and. eliminate the tone of gen.- erator v23". The cam 60 closes the switch 5| which short circuits armature J9" and upper relay contact 20" and serves to continue the elimi nation of the tone of generator23" while shaft 52 is maintainedin its extreme clockwise position. Also, as in the case of Fig. 1, shaft 52 is provided with a cam 62 which serves to close both the switches 63 and, which are shunted across the lower and upper relaycontacts 2|" and 20", respectively, to eliminate the tone. frequencies of both generators 22", 23" as long as the rudder'control shaft 52 remains in its neutral position. as shown.

Fig. 2 also shows schematically a throttle ad: 1

justing arm or lever 65 connected to a throttle control shaft. Adjustment of the arm 65 to rotate shaft: 65 counterclockwise to close the throttle causes difierentiator D'." to operate relay 18" and close the lower relay contact 21",

thereby eliminating the tone of generator 22' from the transmission. Cam 69 and switch 10 serve to continue the elimination of the tone of generator 22"while the shaft 56 remains in its extreme throttle-closing position, the switch 10 servingto sho circuit armature l9"" and con-- Adjustment of arm 65 in the oppositegenerator 23" is continued by the closurefof switch II by the cam 1-2, switch H then short circuiting armature l9' and contact 20". 1 For the purpose of bringing the throttle into its mid-.

position when the control arm 65 is adjusted into its mid-position, the shaft '66 is provided with a cam 12a which closes the switch contacts 10a and Ha uponthe arm 65'being adjusted into its mid-position. Since the closure of switches 10a 7 and Ila serves to short circuit the armature 19" and its upper and lower contacts 20' and 2l', the tone frequencies of both the generators 22 and 23 are eliminated from the transmission.

Fig. 3 shows a difierentiator D"" which may be employed to control special devices on the controlled airplanesuch as a smoke'release device or a device for releasing a bomb. This differentiator and its associateditone generators operate in the same manner as the others above described. The control circuit for D"" is intended to. be connected across theterminals 13, the switch 9"" being thrown to. the right when this differentiator is in use. w r V Fig. '3 also showsa. spare differentiator 13 which is for reserve use and may readily be substituted for any one of those previously described if for any reason a difierentiator becomes disabled. Should the differentiator D of Fig. 1, for

example, become disabled, by throwing its switch 9 to the left and the switch3'l' to the right, it will be disconnected .from the tone generators 2223'- and control of these generators will be taken over by differentiator D and its associated relay I8 Rotation of lever 2 and shaft vI about the longitudinal axis-will then act to control the elimination of the tone frequencies of generators 2223 through thedifferentiator D and its associated relay I8 Fig.3 also shows auxiliary control "means provided for-emergency use in'the control of the throttle, ailerons, elevators'and rudder of the controlled plane.

means R consists of'apair of switches 'IIb and He which representtheleftrudder pedal 54 and The auxiliary rudder control right rudder pedal 55 respectively. Closure of switch llb serves to short circuit the resistor 26 andthereby eliminate the tone frequency of generator 22" from the transmission, while closure'of switch H c short circuits the resistor 30". thus eliminating the tone frequency of 'generator-23 from the transmission. It Willbe understood that the switches 31, 31, (Fig. 1) and 31'', 3lf" (Fig.2) are open when the auxiliary.

controls are used. a

The auxiliary aileron and elevator controlcomprises a miniature control stick' S whichis arranged to selectively actuate and close theswitch contacts 'Hd, He, 'llj and 'l lg. Movement of 1 stick S to close the switch "lid serves to short cirdirection to open the throttle causes the closing of the upper relay contact 20" a'ndthe elimination of the tone of generator 23" from the transmission. With shaft '66 adjusted to full throttle opening position the suppression of the. tone of cult the resistor 26 (Fig. 1) and eliminate the tone-frequency of generator 22 from the transmission,'-thereby operating the'up elevator, while movement of the stick to closeswitch-ll'e serves to short circuit the resistor 30, Fig. 1,:and elimi nate the tone frequency of generator 23 from the transmission; thereby operating the down ele-' vator. Movementof ,stick'S' toclose switch 'llf serves to short circuit the resistor 26', F 1, and thus eliminate the tone frequency of generator 22' from the. transmission to operate the left Movement of the stick to close the. switch 'l lg serves to short circuit theresi stor; 30', Fig." 1, and eliminate the tone frequency.

aileroni of generator'23" from the transmission and open ate the right aileron.

v to channel'E except that its input circuits 18a, Isa are resonant to the frequency of generator 28,

short circuits the resistor 30'. Fig. 2, causing the elimination of the generator 23" from the transmission and theopening of the throttle. Movement of lever T to the right serves to close the switch 1 Ha, which short circuits the resistor 23".

. Fig. 2, thereby causing the elimination of the tone of generator 22" from the transmissionand the closing of the throttle. It will be noted that the switches actuated by th auxiliary controls R, S and T eliminate the tone frequencies of the desired generators by direct connections between the several switches and the output terminals of the generators and not through the differentials D. D. etc., and their controlled differential relays ll, it, etc. While the miniature or auxiliary controls described are not provided with automatic means for obtaining 'synchronizationof'. the V corresponding controlled .yet by holding either of the auxiliary controls in its extreme position a suitable length of time, the corresponding controlled member will be adjusted into its extreme position and be brought into phase with the control member, in case the two have been out of phase or synchronization. i Referring now to Fig. 4 which shows schematically .the apparatus mounted on the controlled airplane for'controlling its ailerons, a receiving" antenna 14 is connected to the input terminals of a tunable radio receiver II which is provided with known means for receiving the carrier wave of transmitter 35 and detecting and amplifying its modulating tone frequencies. The output of receiver" is applied to the tone bus bars 18, to

- which a plurality of tunable amplifying channels E, Ea, E, E'a. etc., responsive to the tone fre-. quencies of generators 22, 23, 22, 23', etc., rerespectively, are connected. Each of these channels is similar in construction and comprises a frequency selective network comprising an isolating resistor 11 and two parallel resonant circuits l8; 19, both tuned to the audio frequency to which the particular channel is responsive. The selected current is amplified in the amplifier tube 80 and rectified in therectifier tube 8|. The rectified output of'tube 81 is amplified in the direct current amplifier tube 82. The plate circuit of amplifier tube 82 actuates a relay 83 and comprises the resistors 84. II and a plate battery 08. One terminal of battery 86 is connected to an adjustable contact 81 which is preferably so adjusted that no direct current flows through the winding of relay '83 when the tone'frequency to which channel E is responsive is not being received. The channel Ea is similar in all respects its output circuit being connected to relay 83a. Relay 83 is provided with a pair of armatures 88, 89 adapted to selectively engage the inner contacts 90, 9| and the outer contacts 92, 93. .Ihe

armature "is connected. as shown. to armature 89a and current is supplied to coil I by a battery Ill. A spring I02 having'one. end connected to a stationarypoint and itsother-end to armature.

96 serves to move pawl I! to the right after th motor circuit, is broken by movable contact ll.

When the relays I3, 834 are'both energized due to the transmission of the tone frequencies of both the channels E and Ea, the energizing circuits of motors 94 and Na are open at contacts 92. 92a so that both motors are at rest. when, however. oneof the relays, as for example. relay ill becomes de-energized, due to the cessation of transmission of the tone of channel E, its upper. contact 82 is closed, thereby completing the circuit of motor 944 and causing its'armature "a to rotate counter-clockwise and move pawl 18 a surncient distance to engage awl Ola behind the next ratchet tooth. The motor circuit is simultaneously broken by movable. contact 81a, where- 'upon'spring ||i2a causes pawl 98a to advance the ratchet 99a one tooth in a counter-clockwise direction. This motion of, armature Ila causes contact 91a to again close the motor. circuit through coil an the motor thus continues to vibrate and advance ratchet "a during the time the tone of oscillator 22 is not being received. Suitable holding pawls. I03. Ina cooperate with the ratchets 99, 99a to. prevent their reverse rotation. Rotation of ratchet wheel "a is communicated by shaft iota. to the input or a diii'erential gearing device I having the output or driven shaft 105. Shaft it! controls the rotationof a driven shaft I 06 through a torque converter or amplifier III! which may be operated bysuitabie power means such as an electric motor M. A driven sprocket wheel Hill is secured to shaft 105 and isin turn connected to the. elevator by a sprocket chain I Illa. The other input shaft ill of differential it is controlled in a similar manner by relay 83a. The torque converter I01 per forms the function of increasing or amplifying the torque supplied by its input shaft ll! and causing its output shaft I00 to rotate in the same direction and through substantially the same angle as its input shaft I III. A suitable torque converter for this purpose is shown and described in the application ofwilliam A. Black. Ser. No.

. lied to shaft l 05 by the impulse motors is of small corresponding contacts of relay 83a are designated a, 89a. For each of therelays ll, 8311a self-vibrating Sla, li2a. 93a and its armatures "a.

motor 94, Me is rovided, these motorsbeing to The movable contact 91 of motor 73 284,64 filed July 15, I939. This arrangement causes the desired adjustment of the airplane elevators and shaft I06. although the torque value.

The arrangement described causes shaft I .and the elevators to remain stationary when the tone frequencies of both oscillators 22 and 23 are being transmitted to the receiver II and this shaft to rotate in one direction or the other, depending upon which of the tones is omitted and its rotation will continue for a period of time equal to the duration of the omission. In the example illustrated, motion of 1lever 2 (Fig. 1) clockwise or forward in the direction of 1' (Fig. 1

causes the elimination ofthe tone frequenc ofgenerator 23, to which channel Ea is responsive,

and the operation 'of motor II and rotation of elevator control shaft I08 to the rightor clockwise. When the movement of the level 2 in the forward direction terminates, the tone frequency of generator 22 continues to be received but the tonefrequency of generator 28 is also received and this causes the actuationv ofx-relay a and the interruption of the circuit of motor 94 at contact 82a, so that both motors are at rest and shaft I06, sprocket wheel I08 and the elevators remain locked in their adjusted position,

Movement of lever. 2 further forwardtoits extreme position in the direction F again causes the elimination of the. tone frequency of generator 23 and operation of motor 94 and consequent;

rotation of shaft I08 to its extreme right position. At this time the tone of generator 22 continues to be received but the extreme movement of sprocket wheel I08 to the right causes the closure and elevator sprocket wheel I08 is assured in the extreme clockwise position, and the elevators are held in their extreme position.

Upon returning control lever 2 toward tor 22zisomitted from the transmission, the chairnel Ea causing the energization of relay 83a and operation of motor 94a and rotation of sprocket wheel I08 to the left toward its-neutral position. This rotation continues until the control lever 2} reaches its neutral position when the tone fre-j quencies of both generators 22 and 23 are omitted from-the transmission in a manner above ex-:

plained. This causes both the relays 83 and 83a to become deenergized, as shown in Fig. 4,so that the circuits of both the motors 84 and 94a are interrupted and both the r'notorsbroughtto a stop.

If sprocketwheel I08 should not be in phase with control lever 2, as, for exaniple, if it is lagging behind lever 2 when the latter reaches neutral position, both the relays 83 and 83a are de-' energized. The circuit including motor coil 95a,

battery IOI, contact 92, contact 83a and movable contact III which cooperates with a cam H2 is closed, causing operation of the motor 84:: and continued rotation of sprocket wheel I08 until it reaches neutral position when 'the motor circuit is broken at contact I and operation of the;

its neu-. tral position, shown in Fig. 1, the tone of generav and comprises the channels E and Ea, which are constructed similarly 'to channels E and Ea above described, except that the resonant circuits of channel E are designed to pass the tone frequency of generator 22 while those of channel E'a pass the tone frequenc of generator 23'. Through the-relays 03 and 88a, which are similar to relays 83 and 83a'; motors 94' and 94a, which are similar to motors 84 and 94a, a differential I04, torque converter I0l' and shaft I 08." an aileron sprocket wheel H5 is operated, this sprocket wheel being connected to the ailerons by a sprocket chain I I5a. Shaft I08"has mounted thereon the cams H0, H2, HM and H3 which cooperate with the movable switch contacts I08, III, Mia and H4, respectively, in the same manner as the cams IIO, II2,'I I21; and H3 cooperate with their respectiveswitch contacts, as above described. I

With the lever 2 in its neutral positiornas shown in Fig. l, neither of the tone frequencies of generators 22 or 23 is transmitted, the relays 83"and 83a are unenergized, motors 94 and 94a are not operated and sprocket wheel II5 remains lockedin position. Upon movement of lever 2 to the left in the direction of arrow L, the tone frequency of'generator 23' only is transmitted which causes the energization of relay 83a, which in turn causes the operation" of motor 84a and rotation of shaft I05 and I06 to the left, so that the aileron sprocket whee1II5 follows lever 2. Should lever 2 beadjusted into its extreme leftward position, the toneof generator 23' continues to be transmitted, in the manner above described in connection with the operation of generator 23 and lever-2. Rotation of shaft I06 to the left,

motor 90a ceases. A similar cam Il2a and mov-"j able contact IIIa serve in a similar manner to secure operation of motor 98 and adjustment of sprocket wheel I08 into its neutral position from} position until the control lever 2 is again moved the opposite direction. Proper in-phase relationship between the elevator control sprocket wheel 0 I08 and the manual control lever 2 in their neu-' 'tral positions also, is thus assured.

A similar operation takes place-in adjusting: the sprocket wheel I 08 and the elevators from their neutralto their extreme left positions.

Movement of lever 2 counter-clockwise or rearwardly in the direction of R, (Fig, 1) causes the elimination of the tone frequency of generator" 22 to which channel E is responsive with the con- ?sequen't operation of relay 83a and motor 84a in amannensimilar'tothat above described in connection .with channel Ea. and-motor 94. I sprocket wheel I08 reaches its extreme left position and is in phase with control lever 2, which II3 causesclosure of contact Ill, which in turn causes the passage of current from battery 88 through the winding of relay 83 and the interruption at contact 92 of the circuit including battery in their extreme counter-clockwise positions, with When i P is now in its extreme'rearward position, a cam 1 therefore, continues, if sprocket wheel I I 5 should causes the closure of movable contact. H4 and the stoppage of motor 94a in the manner above explained in connection with motor 94a and movable contact I I3. Shaft I06 and sprocket wheel I I5 then remain locked in their extremeleftward to the right.

Upon movement of lever 2 to the right in the direction of arrow 1' from its extreme left hand position, the tone frequency of generator 22' only istransrnitted', which causes the energization of relay 83 which in turn causes-the operation of motor 94 and rotation of shaft I06 to the right so that the sprocket wheel I I5 follows the motion of lever 2. 'If lever 2 isadjusted to its neutral position, the tone frequencies of both generators 22 and 23 are omitted from the transmission so that both of the relays 83' and 83a are unenergized. If at this time the sprocket wheel II5 has not yet reached its neutral position, a circuit is established by the operation of c'am II2a' and movable contact Illa, which closes the circuit through the coil of motor 94. The continued operation of motor 94 rotates the sprocket wheel I I5 to' its neutral position when the motor circuit is broken at the contact Illa andoperation of motor 94 ceases, locking the sprocket wheel II5 in its neutral position in phase with control lever 2.

If lever 2 is moved to'the right beyond its" 2,897,476 neutralposition, the tonej o f generator23' con.

tinues to be suppressed, the tone frequency of generator 22' only being transmitted. This causes the energization of relay 83' and the operation'of motor 94', causing the rotationofshaft I06 and Sprocket wheel I I to the right or clockwise. If "control lever 2 is stopped at an intermediate position, the tone frequency of generator 23! is restored to'the'tran'smission so that both the relays 83' and 83a are energized'and the circuit of' motor 94' broken in a manner above explained in connection with the relays 03,8311. and motor 94. Upon moving lever 2. further toward its extreme'clockwise position, the operation of motor 94 is resumed and if at the time lever 2 reaches its extreme clockwise position in the direction indicated by r (Fig. 1) ,the sprocket wheel H5 has not yet reached its extreme position to the right (Fig. 5), the transmission of the tone frequency .of generator 22" continues,

causing continued operation 'of motor 94'. Upon the sprocket wheel I I5 reaching its extreme right hand position in phase with control lever 2, the cam I I0 causes the closure of contact I09 and the stoppage of motor 94 in the manner above explained in connection with motor 94, cam I I0 and contact I09 (Fig. 4). It is thus seen that means is disclosed to provide in-phase relationship between the aileron sprocket wheel and the operators control lever in their neutral positions and also in both their extreme operating positions.

The means provided for operating the rudder of the airplane is shown diagrammatically in Fig. 6, the components corresponding in construction and operation to those above'described in connection with Fig. 5, corresponding parts being indicated by the same reference characters double primed, the rudder control sprocket wheel being indicated at I I6 and being connected to the rudder by means of the chain IIGa. Channel E" is responsive to the tone frequency of generator 22" (Fig. 2) and channel Ea" is responsive -to the tone frequency of generator 23". Depression of, the left pedal 54 (Fig. 2) to move the rudder and sprocket wheel II6 to the left, causes the tone frequency of generator 23" only to be transmitted, which causes the operation of relay'83a" and motor 94a" which rotates shaft I06"- an d sprocket wheel II6 toward the left. Depression of the right pedal 55 causes the transmission of the tone frequencyof generator 22" only, which causes the energization of relay 03" and operation of motor 94" which rotates the sprocket wheel I I6 toward the right through the'differential I04" and torque converter I01". The cams H0", H2", II2a", H3" and their cooperating contacts shown in Fig 6 operate to secure in-' phase relationship between the rudder sprocket wheel H6 and'the control shaft 52 (Fig. 2) at the neutral and both extreme positions of shaft 52 in the same manner as above explained in connection with the corresponding cams and their associated contacts of Fig. 4. The invention thus provides for controlling the rudder of the airplane by means of the conventional two pedals and associated apparatus which is located at the ground station. I

Fig. 6 also shows diagrammatically the means for operating the throttle on the controlled airplane to control its speed. The several components correspond in construction and opera-.

tion to those above described inconnection with Fig. 5, corresponding parts being} indicated. by the same reference characters triple primed, the throttle. control being indicated by a sprocket wheel I II which may be connected to the throttle valve shaft III! by any means as, for example, the chain II9. In this case the channels E' and 1311" are responsive to the tone frequencies of generators 22 and 23' respectively (Fig. 2),

the transmission of the tone of generator 22" only causing rotation of sprocket wheel II I to the right to open the throttle. The transmission of the tone of generator 23' only, causes rotation of sprocket wheel II'I to the left with the consequent closingof the throttle- The cams 0' and 3' and their cooperating contacts I00' and 4' serve to secure in-phase relationship between the sprocket wheel III. and the throttle adjusting lever 65 (Fig. 2) in fully open and fully closed throttle positions respectively in a manner previously described in connecting with the corresponding parts of Fig 4, while the cams 2', 211' and their cooperating contacts III'" and IIIa' respectively, provide in-phase relationship between the sprocket wheel Ill and control lever 05 at the cruising position of the lever and the cruising position of the throttle in the same manner as. previously' described in connection with the corresponding parts of Fig. 4.

I The torque amplifier motors M are shown in Fig. 4,- 5 and 6 as being energized through a circuit including a storage battery I2I, dual switch I25 and the movable switch contact I22 of a relay I23, the winding of relay. I23 being connected to the receiver I5 by the leads I24. This arrangement provides a ready means for permitting the stopping and starting of the torque amplifier motors by the operator at the ground station. With the switch S2 (Fig. 1) open, the carrier frequency is transmitted. thereby causing the-energization of the winding of relay I23, Fig.6, and the starting of the torque amplifier motors M which will continue to operate until the switch S2 is closed. The closing of this switch suppresses the carrier frequency thereby causing the release of relay I23 and the opening of the motor circuits by the relay switch I22 and thereby stopping the motors. From the foregoing it will be readily understood that upon the closure of the switch SI, Fig. 1, by-

the operator and the consequentelirnination'of the tone frequenciesof all the generators 22, 23, 22', etc., from the transmission, each of the conjtrolled shafts I06, I06, I06" and I06'" (Figs. 4

to 6) will be automatically returned to its mid or neutral position by means of the cams II2, II 2a, 2', II 2a, etc., in the manner previously described. Y

In the embodiment illustrated, a manually operable switch I25 is shown as having two switch blades I Ziand 121, the switch'blade I26 serving to close the main ignition circuit I28 of the airplane engine En and the switchblade I21 serving to close the circuit of the torque amplifier motors M in the closed switch position illustrated in Fig. 6. Assuming that relay I23 is being energized due to the transmission of a carrier current, the pilot of the controlled plane mayreadily inter: ruptthe main ignition circuit I20 of the engine and simultaneously break the circuitsupplying current to the motors M by throwing switch I25 to the left from its position shown in Fig. '6. It is thus seen that the switch I25 provides a ready means under the control of the pilot for stopping the engine of the plane and also for stopping the.

motors which operate the torque converters.

As shown in Fig. 4, a pair of telephone receivers I20 may be connectedto thebus bars 16 for use by the safety pilot, should one be on the plane, 

